P04298 · MCEL_VACCW

Function

function

Catalytic subunit of the mRNA capping enzyme which catalyzes three enzymatic reactions: the 5' triphosphate end of the pre-mRNA is hydrolyzed to a diphosphate by RNA 5' triphosphatase; the diphosphate RNA end is capped with GMP by RNA guanylyltransferase and the GpppN cap is methylated by RNA (guanine-N7) methyltransferase. Heterodimeric mRNA capping enzyme catalyzes the linkage of a N7-methyl-guanosine moiety to the first transcribed nucleotide (cap 0 structure), whereas the methyltransferase OPG102 is responsible for a second methylation at the 2'-O position of the ribose (cap 1 structure). Also involved in early viral gene transcription termination and intermediate viral gene transcription initiation. Early gene transcription termination requires the termination factor VTF, the DNA-dependent ATPase NPH-I/OPG123 and the RAP94/OPG109 subunit of the viral RNA polymerase, as well as the presence of a specific termination motif. Binds, together with RAP94/OPG109, to the termination motif 5'-UUUUUNU-3' in the nascent early mRNA.

Catalytic activity

Cofactor

Mg2+ (UniProtKB | Rhea| CHEBI:18420 )

Kinetics

KM SUBSTRATE pH TEMPERATURE[C] NOTES EVIDENCE
23 μMGpppA
A-570 and A-763 mutants have 3-fold and 10-fold higher Km values for GpppA.

Features

Showing features for binding site, site, active site.

Type
IDPosition(s)Description
Binding site37Mg2+ (UniProtKB | ChEBI); catalytic; for RNA triphosphatase activity
Binding site39Mg2+ (UniProtKB | ChEBI); catalytic; for RNA triphosphatase activity
Site77Essential for RNA triphosphatase activity
Site107Essential for RNA triphosphatase activity
Site126Essential for RNA triphosphatase activity
Site159Essential for RNA triphosphatase activity
Site161Essential for RNA triphosphatase activity
Binding site192Mg2+ (UniProtKB | ChEBI); catalytic; for RNA triphosphatase activity
Binding site194Mg2+ (UniProtKB | ChEBI); catalytic; for RNA triphosphatase activity
Active site260N6-GMP-lysine intermediate
Binding site549-550S-adenosyl-L-methionine (UniProtKB | ChEBI)
Binding site569-570mRNA cap of mRNA (UniProtKB | ChEBI)
Binding site573S-adenosyl-L-methionine (UniProtKB | ChEBI)
Binding site598S-adenosyl-L-methionine (UniProtKB | ChEBI)
Site607mRNA cap binding
Binding site620S-adenosyl-L-methionine (UniProtKB | ChEBI)
Site632mRNA cap binding
Binding site678-680S-adenosyl-L-methionine (UniProtKB | ChEBI)
Site682mRNA cap binding
Site763mRNA cap binding
Site836mRNA cap binding

GO annotations

AspectTerm
Cellular Componentvirion component
Molecular FunctionGTP binding
Molecular Functioninorganic triphosphate phosphatase activity
Molecular Functionmetal ion binding
Molecular FunctionmRNA 5'-cap (guanine-N7-)-methyltransferase activity
Molecular FunctionmRNA 5'-triphosphate monophosphatase activity
Molecular FunctionmRNA guanylyltransferase activity
Molecular Functionpolynucleotide 5'-phosphatase activity
Molecular FunctionRNA binding
Biological ProcessDNA-templated transcription termination

Keywords

Enzyme and pathway databases

Names & Taxonomy

Protein names

  • Recommended name
    mRNA-capping enzyme catalytic subunit
  • Alternative names
    • Virus termination factor large subunit (VTF large subunit)
    • mRNA-capping enzyme 97 kDa subunit
    • mRNA-capping enzyme D1 subunit
    • mRNA-capping enzyme large subunit

Including 3 domains:

  • Recommended name
    Polynucleotide 5'-triphosphatase
  • EC number
  • Alternative names
    • mRNA 5'-triphosphatase (TPase)
  • Recommended name
    mRNA guanylyltransferase
  • EC number
  • Alternative names
    • GTP--RNA guanylyltransferase (GTase)
  • Recommended name
    mRNA (guanine-N(7))-methyltransferase
  • EC number
  • Alternative names
    • mRNA cap methyltransferase

Gene names

    • Name
      OPG113
    • ORF names
      D1R
    • Ordered locus names
      VACWR106

Organism names

Accessions

  • Primary accession
    P04298
  • Secondary accessions
    • Q76ZS6

Proteomes

Subcellular Location

Virion
Note: All the enzymes and other proteins required to synthesize early mRNAs are packaged within the virion core along with the DNA genome.

Keywords

Phenotypes & Variants

Features

Showing features for mutagenesis, natural variant.

Type
IDPosition(s)Description
Mutagenesis77-79Almost complete loss of RNA triphosphatase activity, 70% loss of guanylyltransferase activity.
Mutagenesis107Complete loss of triphosphatase activity, no effect on guanylyltransferase activity.
Mutagenesis126Complete loss of triphosphatase activity, no effect on guanylyltransferase activity.
Mutagenesis135-13670% loss of RNA triphosphatase activity, 40% loss of guanylyltransferase activity.
Mutagenesis159Complete loss of triphosphatase activity, no effect on guanylyltransferase activity.
Mutagenesis161Complete loss of triphosphatase activity, no effect on guanylyltransferase activity.
Mutagenesis192-194Complete loss of RNA triphosphatase activity, 50% loss of guanylyltransferase activity.
Mutagenesis260Complete loss of guanylyltransferase activity, no effect on RNA triphosphatase activity.
Mutagenesis524-52650% loss of RNA triphosphatase activity and 40% loss of guanylyltransferase activity.
Mutagenesis570Retains substantial methyltransferase activity in vitro; lethal in vivo.
Mutagenesis573Complete loss of methyltransferase activity; lethal in vivo.
Mutagenesis607Retains substantial methyltransferase activity in vitro; lethal in vivo.
Mutagenesis608Almost complete loss of methyltransferase activity; lethal in vivo.
Mutagenesis676Complete loss of methyltransferase activity; lethal in vivo.
Mutagenesis679Almost complete loss of methyltransferase activity; lethal in vivo.
Mutagenesis682Complete loss of methyltransferase activity; lethal in vivo.
Natural variant705in strain: mutant Dts36
Mutagenesis763Retains substantial methyltransferase activity in vitro; lethal in vivo.

Variants

We now provide the "Disease & Variants" viewer in its own tab.

The viewer provides 1 variant from UniProt as well as other sources including ClinVar and dbSNP.

Go to variant viewer

PTM/Processing

Features

Showing features for chain.

TypeIDPosition(s)Description
ChainPRO_00002101241-844mRNA-capping enzyme catalytic subunit

Interaction

Subunit

Forms a heterodimer with the regulatory subunit OPG124.

Binary interactions

TypeEntry 1Entry 2Number of experimentsIntAct
BINARY P04298OPG124 P043183EBI-16095746, EBI-16095776

Protein-protein interaction databases

Family & Domains

Features

Showing features for region, domain.

Type
IDPosition(s)Description
Region1-539Triphosphatase-guanylyltransferase
Domain516-844mRNA cap 0 methyltransferase

Domain

The N-terminus contains the triphosphatase and guanylyltransferase domains, whereas the C-terminus contains the methyltransferase domain. The N-terminus is involved in binding to the termination motif 5'-UUUUUNU-3' in the nascent mRNA.

Sequence similarities

In the N-terminal section; belongs to the dsDNA virus mRNA guanylyltransferase family.
In the C-terminal section; belongs to the class I-like SAM-binding methyltransferase superfamily. mRNA cap 0 methyltransferase family.

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Length
    844
  • Mass (Da)
    96,734
  • Last updated
    1987-03-20 v1
  • MD5 Checksum
    75C8086390B222FC389AEA9468829EE5
MDANVVSSSTIATYIDALAKNASELEQRSTAYEINNELELVFIKPPLITLTNVVNISTIQESFIRFTVTNKEGVKIRTKIPLSKVHGLDVKNVQLVDAIDNIVWEKKSLVTENRLHKECLLRLSTEERHIFLDYKKYGSSIRLELVNLIQAKTKNFTIDFKLKYFLGSGAQSKSSLLHAINHPKSRPNTSLEIEFTPRDNETVPYDELIKELTTLSRHIFMASPENVILSPPINAPIKTFMLPKQDIVGLDLENLYAVTKTDGIPITIRVTSNGLYCYFTHLGYIIRYPVKRIIDSEVVVFGEAVKDKNWTVYLIKLIEPVNAINDRLEESKYVESKLVDICDRIVFKSKKYEGPFTTTSEVVDMLSTYLPKQPEGVILFYSKGPKSNIDFKIKKENTIDQTANVVFRYMSSEPIIFGESSIFVEYKKFSNDKGFPKEYGSGKIVLYNGVNYLNNIYCLEYINTHNEVGIKSVVVPIKFIAEFLVNGEILKPRIDKTMKYINSEDYYGNQHNIIVEHLRDQSIKIGDIFNEDKLSDVGHQYANNDKFRLNPEVSYFTNKRTRGPLGILSNYVKTLLISMYCSKTFLDDSNKRKVLAIDFGNGADLEKYFYGEIALLVATDPDADAIARGNERYNKLNSGIKTKYYKFDYIQETIRSDTFVSSVREVFYFGKFNIIDWQFAIHYSFHPRHYATVMNNLSELTASGGKVLITTMDGDKLSKLTDKKTFIIHKNLPSSENYMSVEKIADDRIVVYNPSTMSTPMTEYIIKKNDIVRVFNEYGFVLVDNVDFATIIERSKKFINGASTMEDRPSTRNFFELNRGAIKCEGLDVEDLLSYYVVYVFSKR

Keywords

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
M15058
EMBL· GenBank· DDBJ
AAA48253.1
EMBL· GenBank· DDBJ
Genomic DNA
AY243312
EMBL· GenBank· DDBJ
AAO89385.1
EMBL· GenBank· DDBJ
Genomic DNA

Genome annotation databases

Similar Proteins

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